My camera on my iPhone 4 is showing nothing but a black screen. Front and rear camera and it happens in all camera related apps as well. When I reset my phone it fixes it, but the problem keeps reoccurring. How do I permanently fix the problem?
Is the phone jailbroken? If so, try running it not jailbroken for a while to see if the problem reoccurs.
Other than that, try an OS restore - just make sure you do a backup first.